Oracle PL/SQL/Analytical Functions/First Last — различия между версиями

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м (1 версия)
 
(нет различий)

Версия 13:45, 26 мая 2010

FIRST and LAST functions to get the first and last values in an ordered group

SQL> CREATE TABLE all_sales (
  2    year INTEGER,
  3    month INTEGER,
  4    prd_type_id INTEGER,
  5    emp_id INTEGER ,
  6    amount NUMBER(8, 2)
  7  );
Table created.
SQL>
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,1    ,1          ,21    ,16034.84);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,2    ,1          ,21    ,15644.65);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,3    ,2          ,21    ,20167.83);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,4    ,2          ,21    ,25056.45);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,5    ,2          ,21    ,NULL);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,6    ,1          ,21    ,15564.66);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,7    ,1          ,21    ,15644.65);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,8    ,1          ,21    ,16434.82);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,9    ,1          ,21    ,19654.57);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,10   ,1          ,21    ,21764.19);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,11   ,1          ,21    ,13026.73);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2006,12   ,2          ,21    ,10034.64);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,1    ,2          ,22    ,16634.84);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,1    ,2          ,21    ,26034.84);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,2    ,1          ,21    ,12644.65);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,3    ,1          ,21    ,NULL);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,4    ,1          ,21    ,25026.45);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,5    ,1          ,21    ,17212.66);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,6    ,1          ,21    ,15564.26);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,7    ,2          ,21    ,62654.82);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,8    ,2          ,21    ,26434.82);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,9    ,2          ,21    ,15644.65);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,10   ,2          ,21    ,21264.19);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,11   ,1          ,21    ,13026.73);
1 row created.
SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)
  2                  values(2005,12   ,1          ,21    ,10032.64);
1 row created.
SQL>
SQL> select * from all_sales;
      YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT
---------- ---------- ----------- ---------- ----------
      2006          1           1         21   16034.84
      2006          2           1         21   15644.65
      2006          3           2         21   20167.83
      2006          4           2         21   25056.45
      2006          5           2         21
      2006          6           1         21   15564.66
      2006          7           1         21   15644.65
      2006          8           1         21   16434.82
      2006          9           1         21   19654.57
      2006         10           1         21   21764.19
      2006         11           1         21   13026.73
      2006         12           2         21   10034.64
      2005          1           2         22   16634.84
      2005          1           2         21   26034.84
      2005          2           1         21   12644.65
      2005          3           1         21
      2005          4           1         21   25026.45
      2005          5           1         21   17212.66
      2005          6           1         21   15564.26
      2005          7           2         21   62654.82
      2005          8           2         21   26434.82
      2005          9           2         21   15644.65
      2005         10           2         21   21264.19
      2005         11           1         21   13026.73
      2005         12           1         21   10032.64
25 rows selected.
SQL>
SQL> --FIRST and LAST functions to get the first and last values in an ordered group.
SQL>
SQL> --You can use FIRST and LAST with the following functions: MIN(), MAX(), COUNT(), SUM(), AVG(), STDDEV(), and VARIANCE().
SQL>
SQL> SELECT
  2   MIN(month) KEEP (DENSE_RANK FIRST ORDER BY SUM(amount))
  3    AS highest_sales_month,
  4   MIN(month) KEEP (DENSE_RANK LAST ORDER BY SUM(amount))
  5    AS lowest_sales_month
  6  FROM all_sales
  7  GROUP BY month
  8  ORDER BY month;
HIGHEST_SALES_MONTH LOWEST_SALES_MONTH
------------------- ------------------
                  5                  7
SQL>
SQL>
SQL>
SQL> drop table all_sales;
Table dropped.
SQL>
SQL>